IUBMB Enzyme Nomenclature


Accepted name: 2'-5' oligoadenylate synthase

Reaction: 3 ATP = pppA2'p5’A2'p5’A + 2 diphosphate

Glossary: pppA2'p5’A2'p5’A = 5'-triphosphoadenylyl-(2'→5')-adenylyl-(2'→5')-adenosine

Other name(s): OAS

Systematic name: ATP:ATP adenylyltransferase (2'-5' linkages-forming)

Comments: The enzyme is activated by binding to double-stranded RNA. The resulting product binds to and activates RNase L, which subsequently degrades the RNA. Oligoadenylates of chain lengths 2, 4 and 5 are also produced. The dimer does not have any known biological activity [2].

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number:


1. Kerr, I.M. and Brown, R.E. pppA2'p5’A2'p5’A: an inhibitor of protein synthesis synthesized with an enzyme fraction from interferon-treated cells. Proc. Natl. Acad. Sci. USA 75 (1978) 256-260. [PMID: 272640]

2. Martin, E.M., Birdsall, N.J., Brown, R.E. and Kerr, I.M. Enzymic synthesis, characterisation and nuclear-magnetic-resonance spectra of pppA2'p5’A2'p5’A and related oligonucleotides: comparison with chemically synthesised material. Eur. J. Biochem. 95 (1979) 295-307. [PMID: 456356]

3. Hartmann, R., Justesen, J., Sarkar, S.N., Sen, G.C. and Yee, V.C. Crystal structure of the 2'-specific and double-stranded RNA-activated interferon-induced antiviral protein 2'-5'-oligoadenylate synthetase. Mol. Cell 12 (2003) 1173-1185. [PMID: 14636576]

4. Hovanessian, A.G. and Justesen, J. The human 2'-5'oligoadenylate synthetase family: unique interferon-inducible enzymes catalyzing 2'-5' instead of 3'-5' phosphodiester bond formation. Biochimie 89 (2007) 779-788. [PMID: 17408844]

[EC created 2013]

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